The invention relates to a device for setting a self-drilling clamping fastener with clamping jaws held in a sleeve-like reception part for gripping a traction mandrel of the clamping fastener, wherein the reception part has an outer threading at its end that is turned away from the clamping jaws and engages a threaded bore of a driving sleeve that can be coupled with a rotary drive, wherein the reception part can be kept from turning.
In a known device for the setting of blind rivets (EP-A-0 213 101), a pot-like bushing is rotatably arranged in a housing, wherein this bushing is, on the one hand, provided with an inner thread and, on the other hand, is tightly connected with the rotary drive. A reception part, carrying the clamping jaws for a traction mandrel of the blind rivet, is provided at its rearward end with an outer thread, wherein this outer thread engages the inner thread of the bushing. During the drilling process, all parts of this device rotate, i.e., also the externally located housing. Upon completion of the drilling process, the direction of rotation of the device must be reversed, for which purpose the housing itself must remain in a fixed position. Either the housing may be prevented from rotating further by holding it in place, or the housing may move a short distance, while the direction of rotation is changed in the direction towards the rotary drive, and is then present at one housing portion.
Upon setting the blind rivet, the direction of rotation of the drive must again be changed in order to bring the reception part carrying the clamping jaws back into the initial position. For this purpose, the housing must be held manually in order to effect an axial movement of the reception part due to the thread engagement. On the one hand, it is problematic when with a setting device in a driven part, a manual intervention has to take place; on the other hand, there exists the danger that during unintentional activation, for example during the drilling process, the operator may be burned as a result of the great generation of heat.
Furthermore, a setting device for blind rivets has become known (EP-A-0 456 269) which works approximately on the same principle as the previously mentioned setting device. Here, an additional coupling is simply provided between the driving sleeve, having the inner thread, and a driving part that can be mounted directly to the driving device, wherein this coupling can be released in that, during retraction of the section of the receiving part provided with the outer thread, after a certain path abuts against the free end of same and penetrates the driving part directly connected with the driving device until the coupling is released. Also with this arrangement, it is absolutely necessary that the user manually intervene at the housing in order to introduce pulling movement after a drilling process, during which the entire setting device portion rotates.